[PATCH v3 01/10] drivers: PL011: avoid potential unregister_driver call

[moorray3@wp.pl (Jakub Kiciński)]

On Thu,  9 Apr 2015 12:29:12 +0100, Andre Przywara wrote:
> Although we care about not unregistering the driver if there are
> still ports connected during the .remove callback, we do miss this
> check in the pl011_probe function. So if the current port allocation
> fails, but there are other ports already registered, we will kill
> those.
> So factor out the port removal into a separate function and use that
> in the probe function, too.
> 
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  drivers/tty/serial/amba-pl011.c |   37 +++++++++++++++++++++----------------
>  1 file changed, 21 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index f5bd842..d08951f 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2135,6 +2135,24 @@ static int pl011_probe_dt_alias(int index, struct device *dev)
>  	return ret;
>  }
>  
> +/* unregisters the driver also if no more ports are left */
> +static void pl011_unregister_port(struct uart_amba_port *uap)
> +{
> +	int i;
> +	bool busy = false;
> +
> +	for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
> +		if (amba_ports[i] == uap)
> +			amba_ports[i] = NULL;
> +		else if (amba_ports[i])
> +			busy = true;
> +	}
> +	pl011_dma_remove(uap);
> +	if (!busy)
> +		uart_unregister_driver(&amba_reg);
> +}
> +
> +

Double new line.